Machine for grinding metal



y 1945. E. BANNISTER 7 2,375,340

' MACHINE "FOR GRINDING METAL Filed Oct. 28, 1942 10 Sheets-Sheet lInvefitor 4 By 'r. i

1945. E. BANNISTER MACHINE FOR GRINDING METAL 1 0 Sheets-Sheet 2 FiledOct. 28, 1942 I y 1945. E. BANNlSTER 2,375,340-

MACHINE FOR GRINDING METAL Filed Oct. 28, 1942- 10 SheetsSheet 3Inventor 43 4 75 May 8, 1945 E. BANNISTER MACHINE FOR GRINDING METAL 1OSheets-Sheet 4 Filed 001;. 28, 1942 I Ihvqnlor I Man /sf mrwt y 1945. E.BANNISTER MACHINE FOR GRINDING METAL Fild Oct. 2 8, 1942 10 Sh'eets-Sheet 5 Inventor .MI/Wffib- Atlorng s ,E. BANNISTER MACHINE FORGRINDING METAL.

10 Sheets-Skeet 6 Filed Oct. 28, 1942 lLl In ventbr Attorney;

y 19.45. E. BANNISTER MACHINE FOR GRINDING METAL 1o Sheets-Shet 7 FiledOct. 28, 1942 In veri'tor dwvnsrag,

Atlornea May 8, 1945.

E. BANNISTER MACHINE FOR GRINDING METAL 1 Filed Oct. 28, 1942 10Sheets-Sheet 8 In ventbr ifimvmsrea Attorney E. BANNISTER MACHINE FORGRINDING METAL May 8, 1945.

Filed Oct. 28, 1942 10 Shets-Sheet 9 Attorner May 8, 1945.

E. BANNISTER MACHINE FOR GRINDING METAL Filed 001;. 28, 1942 10Sheets-Sheet 1o In ventr l-dl/YM/SIZL I 5 Attorney different metals.

Patented May 8, 1945 UNITED STATES PATENT oFncs MACHINE For. GRINDINGMETAL Edgar Bannister, London, England, assignor to D. Gilson andCompany Limited, London, England, a company of Great BritainAppeal-associates 28,1942, Serial No. 463,682

In Great Britain Novemberl29, 1941 20 Claims.

The invention relates to machines for grinding metal surfaces, and hasparticular reference to the grinding of the lands ofscrew dies of theso: called button type.

In finishing screw dies, particularly those made for precision work, itis necessary to grind accurately the leading face of each land. In orderto produce the best cutting edge, the angle of the leading face to theradial line passin through the cutting edge mustbeqaccurately defined,although it may be different-for dies for cutting It is also importantthat the leading faces of the different lands shall be equally spacedangularly around the die, that is to say in thecase of a 4 -land die,for example, the leadingfedges must be accurately spaced 90? apart;furthermore, of course, the leading-edges must all be equally spacedfrom the centre of the die. These latter two requirements are necessaryif all the lands are to do the same amount of work and screw threadsofthe accuracy necessary in precision work are to becut For thisfinalfinishing by grinding, it is fairly usual nowadays to use a smallgrinding wheel ofa suitable abrasive material which has to be of "smalldiamete r in relation to its length sothat it takes the shapeo'f apencil which is rotated accurately about its axis at-very high speed Aconvenient form of such a grindingvwheel is what is called an air-drivenpencil sinceit is justed to fix the amount of feed. Then the actualshape of the leadingedge of each land of the die is determined bymounting the grinding pencil on a pantograph mechanism furnished with astylus which the operator keeps in contact with an enlarged copyof thedesired leading face.

For convenience it can bearranged that the op-,

number of lands are often produced. Therefore,

when the leading face of one land has been gr und it is necessary to beable to rotate the die in its holder accurately through the desiredangle-which in the case of a four-land die'is an angle of 90f -s o thatthe leading face of the next land can be shaped accurately to the sameshape as the first land but at an angle around the die which is exactly90 in the example of afourland die with respect to the leading face ofthe first land. To facilitate this procedure, the die holder isprovidedwith a registering device which rotated at high speed by comp ressedfairactingon'whatamo'untsto a small air turbine, the rotor of which is ontherear end of the grinder spindle. If the die tobe finished is mountedin aholder andthe grinding pencil is on a carriage or sup: port which ismoved by hand by the operator while the pencil can be ,reciprocated in'the direction of its axis, .it is clear that the accuracy of thefinished job depends almost entirely on the skill of the operator. i

- The object of the present invention is to produce, a precisoni machinewhich can be. used by an unskilled .or' 'relatively unskilled operatorand yetproduces accurately. in everydie the necessary conditions whichhave been set out above.

According to the .present' invention, such a amount about its axis andthe totalamount of l that feed can be predetermined since the rotationis effected by the operator 'turningawheel it is brought up against astop whichis' pre-ador handle until the handle or apartintegral with rcan hold it accurately in anumber of positions spaced apartbythenecessary angle depending upon the number of lands. The registeringdevice may consist of the appropriate number of recesses in theperiphery of the holder engaged by a pivoted tooth carried on theholderalthough, of course, the converse arrangement might be employed.Between the feed handle which may rotate'the die holder through wormgearing, and the die holder itself, a one-way clutch which mayconveniently be a roller clutch without backlash,

is provided. Then, as the" cut is applied by rotating the die holder,owing to the shape of the recess and the engaging'tooth, the latter isgradually forced out of the recess until it rides on I the periphery' oftheholder, the. drive being through the aforesaid one-way clutch. Then,by

rotatingthe die holder in the same direction so because the die holderis held by the; tooth and recess. The procedure is then repeated untilall the lands have been similarly. accurately ground.

7 :In such a machine the grinding pencil, of course, is subject toslight wear and after. a time the surface'tends to become glazed. It isnecessary to be able todress the grinding pencil, and the presentinvention provides *for that dressing while compensatingior the slightlyreduced diameter of thegrinding pencil without loss of accuracy in thegrinding. For that pur' pose; the die holder is mounted on. acrosse'slide with an operating wheel properlyindexed which enables thedie holder to be moved slightly acrossv the machine.

The dressing diamond is' provided merely with a holder the body of whichcan be set in the machine in the die l-ic'ilder in sueh a position thatwhen the grinding pencil is centred in the machine, which can beefiecte'd by serting a locking taper pinin the pantograph r'nechanism,the pencil, before it has been' reduced in diameter, takes up a centralposition in a central bore inthe dresser body and can be rotatedtherein. The diamondvcarrier is set radially thebody so-that it can bebroughtaccurately up to the surface of the grinding pencil for thedressing feed. For that purpose, a pm of the-same diameter as thegrinding pencil is introduced through'a bore at the top which it fitsaccurately and the diamond is set accurately just in contact with thepin Whichisthen withdrawn. The grinding pencil is then brought up intothe central position and jthe-cross-slide referred to is advanced thenecessary amount and line III-III in Figure 2, Figure 3 againillustrating the left-hand side of the machine, and Figure 3a. theright-hand side of the machine;

Figure 4 is an elevation of the machine seen from the right of Figure 3,the view being shown partly in section on the line lv lv in Figure 3a;

Figure 5, is a perspective view showing the main parts of the pantographlinkage employed; Figure 6 is a vertical section showing the main pivotsof the pantograph;

i Figure 7 is a central vertical section of the die I holder and itsdriving mechanism, and also showthe diamond takes a slight out on theperiphery of the grinding pencily If no furtherprovisions were mad andthe grindingof the die were proceeded with; it is obvious because of thereduced diameter of thegrinding pencil that the next cut would beslightly less deepthari the immediately preceding out before thegrinding pencil were dressed. 1 This is corrected or compensated-for,however, by leaving the die holder in the slightly adjusted position ithas been given by means of the cross feed so that in effect the die hasnow;

beenslightly placed out of'centrerelative to its previous position by anamount equal'to the cut.

taken off the surface of the grinding pencil.

adjustment of the die, the next land of the die will be cut inexactly-the same way as the pace-- ceding land is cut. j I Q *1 K Forconvenience in such a machine, the grind- Thus; when grinding nextproceeds, owing to this shaft 1 to the driven sleeve 6 so that themachine ing pencil is not given a vertical reciprocation atell, but'whenthe jp'antograph is unlocked,

' it can only move in a horizontal plane inaccordanc ewith the shape ofthe'pantographcopypiece. The die holder, howevenis mounted on a carrierwhich includes the worm mechanism for producing the feeding cut, andthis carrier is mounted was to be capable of vertical reciprocationunder" the action of camsona cam shaft which extends from right to leftacross the machine below the carrier;

derstood and readily carried into effect, a ma- Ifo'rgrinding afour-land button die will now be described byway of examr'il withreference :to the accompanyingdrawings', in'which: "Figure 1 isaperspective View of the'outside of-the complete machine Figures Zand2a. show a plan of the machine,

Figure 2 depicting the left-hand side,--'and-Figure zaithe. right-handside of the machine Figures 3 and 3a show a vertical section on the.

mg t e inding pen l;

Figure 8 is. a horizontal section on VIII-VIII in Figure 7;

Figure 9 is an elevation ofa detail seen from the front of the machinein the direction ofthe row X in Figure 4; V s

Figure 10 is an elevation, with the lower part in section, f thecompressed air motor for the grinding pencil; I I 1 Figure 11 is adiagram to an enlarged scale of a die to be ground;

Referring first ofall to Figures 1 to 4 the ma: chineshown as aniexampleis a small bench inachihe housed in a casting l and driven by asmall'electric motor 2,1who s'e shaft 3 runs from the back of themachine towards the front at'the right-hand side of the machine; as bestseen in Figure'2a. The motor 2'' drives a worm 4 and a worm wheel5,-which latter-is carried by a sleeve 6 which is journalled to turnabout a cam shaft! of the machine which runs transversely across themachine from the right-hand side. The

movable member 8; ofa dog clutch iskeyedjtothe I shaft 1 and; can beshifted to the right in Figure Sate clutcnthe cam shaft 1; to a handwheel 9;

The member 8 also has dog teeth its opposite r or left-hand side in Fi ue 3wwhich, when the membergais moved to th left," clutches thecam can beturned slowly by hand by the hand wheel 9 or can be power driven.Theclutch member is actuated by a control lever in the'form" ef -ajoystick [Wmounted for transverse'movement from left to right of themachine, and for foreand-aft movement vfrom back 1 to, front of themachine. "During the transverse moveme'nt .it

' has three definite positionslocated by spring- "In order that theinvention may be eleafly chine in accordance-with the invention designedpressed balls H (Figure 4); When th joystick I0 is moved tothe leftintol the' position Illa shown in Figure 21;, it rocks a fork l2 tocause the clutch member 8- to engage the sleeve 6. jWhen thejoysticlg isin the middle'positiomthe clutch member 8- is disconnected, and when itis moved to the right hand positionshewn; atiflb infigure 2c, the clutchmember 8 is connected to the hand wheel 9. During thefore-and-aftmom m'o eiqv i k. Uta va v 1 c nt l neth sumflyv f presse air o t e rindi g we l mechanism isoperated. Compressed air: issup pliedithrough a pipe:Hand the valve l-3 controls its passage'to a flexible pipe iii-which isconnected be'described later. The lever lo ispivoted at its to the airmotor for the grinding pencil, as will the line the l-gr-inding pencilshown in positionin the I lower end at 15, and when in the full linposition shown at Ill in Figure 4,the valve I3 is pushed backward fromthe position shown in Figure 2a to shut off the connection between thepipes l4 and 15. When the joystick is turned intothe position shownindotted lines at in Figure 4, the valve 13 is moved into the positionshown in Figure 2a to allow the supply of compressedair to pass to themachine through the pipe 15. The

lever moves between the lugs2-l6 of its pivot bracket ,and these lugsare furnished-with pips its ,fore-and-aft positions 2|! for indexing itin I00, 1..

The grinding wheel mechanism seen Figure 3a but shown in detail inFigure l 0,-compris'es a casing ll mounted on and extending...'upwards,from a bracket Ila carried. on a horizontal link-1'8 of the pantographlinkage. assemblycan beadjusted from back to front of the machine on aslide .19 on. the link I8v and is locked in the adjusted positionbymeans of a setscrew 20. The compressed air pipe l5 is connected to aninlet nipple 2i communicating with a passage 22 in the base 23 of thegrinding'wheel mechanism. Th passage 22 is continued as a nozzle 24 in aplate 25 so that jets-of air are injected into the blades of a bladedwheel-'26. The, .wheel 26 is fixed: to'the lower end of -the spindl 21of the grinding wheel or'pencil 28 and which is a cylindrical pencil ofv.emery or other abrasive composition. The spindle" 21 is journalled inthe casing l1 and the'air escaping from the wheel 26 passes upwardlythrough the casing H, as indicated by the arrows 29 in Figure 10,- andtherefore serves the purpose of cooling the bear ings of the spindle 2'!and also of blowing'away any fine dust removed from the die undertreatment by the grinding pencil 28. i

The pantograph linkage is best seen in Figures 2, 2a, 3, 3a, 5 and 6. Itconsists of a parallelogram linkage consistingof two pairs of parallellinks I8, 30, 3|, 32, hinged together at-thecorners.

As already stated, the grinding wheel-mechanism; is mounted on thelinkl8 which is hinged to the link 3| about a pivot 33'. I This pivot;asshowndn Figure 6, isoffset from another-pi'vot-34 which is the mainfulcrum of the-mechanism and is'set-in the bottom plate 35 came machineThe link 30 is steadied by means of-a pair of auxiliary links The.grinding wheel The tracing point 42 is arranged to be moved over a small.table 52 secured tothe casting of the machine and arranged to carry acopy-piece or pattern 53 which has a rib 54 which bears the same profilas the faces of the die to be ground. When the pantograph linkage isshifted so that t the grinding pen'cil28 takes up a central positionwithin the die holder, the pantograph linkage can be lockediin' thatposition by the insertion ofa tapered plug 55 into holes in the maincasting I and passing through a hole in the rod 44,-as seen in Figures 2and 3. The grinding pencil 28 is only able to move in a horizontal planeunder control of the tracing point 42 of the pantograph mechanism and isnot mounted for up and down movement in a vertic'al plane;

on the other hand, the die'holder shown in' detail in Figures 7 and 8 ismounted to slide up and down, being fixed to two supporting pillars 56,51 whose axes lie on the transverse centre line of the die holder, ascan be seen in Figure 2a, and

6' a front central steadying column .38v whichis merely guided in guides59 in the framework casting of the machine so as to prevent any rockingof the die holder'when the latter is raised or low ered; The die holderis raised and lowered'by ,means of the pillars and 5'! which arecamoperated from the cam shaft 1; This mechanism is seen best in Figures3a and 4. Each of the pillars 56,51 has at the lower end an'adjustabletapioet-like member 59, Bil, adjustable by means. 7

of screws '61-, 62 and locked in theadiusted position by lock nuts t3,64. The tappets"59, -60 have large heads which rest on operating rollers65,55, as best seen in Figure 4. Each'ofthese rollers is carried atthefree end of an arm 6l'pivoted towards the back of themac'hine'at 58andeach as, 3 1, the link 36 being pivoted at-38=to=the pantograph link andat 39 to the 31, the latter being pivoted to the bottom plate at thepoint 40. The upper link I8 is also steadied in a simi lar way by apairof links not shown in Figure-5, but one of which appears at-4l inFigure 3a,- and turns about a vertical pivot fixed to the casingfiot themachine, and alsopivoted toa second link which in its. turn is pivotedto the-bracket -l1 asecured to the pantograph link I 8.- The stylus ortracing point 42 is carried-in a head 43"which can .be adjusted alongarod 44 andsecuredin position by alocking screw 45:- The rod 44 isrigidly fixed by a bracket 46 in line'with thecentreofthe link 32. Itwill, therefore, be seen that'by moving the tracing point 42,- thelinkage I8-, 30-;31, 32, turns freely about the main fulcrum pivot 34,an'dfthe different links can turnabout the pivotswhich formthe hingesbetween each pair of links; The,

equivalent pantograph'mech anism is indicated by the three lines4'l; 48and 49 in'Figuresi2 and 2a.

v The intersecting point 50- between thelines 41 and 48 represents thepositionof the axis of the main fulcrum 34 of the pantogr'aph'llnkag 'e.The axis of the pencil -28is located at the point-i5! in thecntrelineof'the link '18. already men-f the assembly can be movedslightly from right to The sliding surfaces are of the arms at itsmid-length has a rolleror cam' follower 69 which restson the respectivecam '10 on the cam shaft 1. The cams 1B are of the same shape andoperate in unison to lift the arms 61 together so that the rollers 65lift the pillars .56,

5! and'with them the whole die holder assembly. The latter'descendsunder its own weight'or under spring tension which retains the tappets59, B0 in contact with the rollers 65, 66. v

Thewhole of the die holder assembly, including the pillars.56, 51, theguides H, I2 in which they slide, and the steadying pillar or column 58,

and the guide 59 in which it slides, is mounted on a slide on themachine bed by means of which left of the machine. seen at 13 in Figure4, and the usual packing gibs are shown at 14. The sliding movement iseffected by a screw-threaded spindle "15 carrying an index wheel 15, thelatter bearing against a surface 11 on the main frame casting l, and thethreaded spindle'l5 engaging a-threaded nut member 18 which is rigidwith the dieholder assembly. Ac-

cordingly, by rotating the hand wheel 16, the

Whole or the assembly is moved tothe right or l'eft on the slidingsurfaces 13 by apredetermined; amount. A locking screw for this slide isprovided at 19 and this naturally has to be slackened back before thedie holder assembly can, be moved.

Th die b ld r s m l s et in o a ze o De tion when the grinding pencil-isnew and hasnot has been movedfore-and-aft to admit the supply ofcompressed air to the grinding pencil'assembly as already indicated,andthe cam shaft I of the machine has been clutched to the driving motorby moving the control lever III into the left-hand,

position Illa in Figure 2a, with the result that the grinding pencil 28is rapidly rotated and the die holder 80 carrying the die 82 isreciprocated up and down so that grinding on the leading face of theland of the die goes on. This process is con tinued until the stopsurface 96 on the arm 95 (Figure 9) reaches the predetermined stopmember I00, at which time it is known without any exercise of skill onthe part of the operator that the grinding out has been taken to thedesired depth and exactly the correct amount of metal between the linesI I and II I in Figures 11 and 12 has been removed.

It will be observed thatfone face of each of the recesses I02 is shownin Figure 8 to be more inclined'than the other so'that as the di 82 isrotated counterclockwise in Figure8 and the feed goes on, the tooth I04is gradually forced out of the recess I02 with which it is engaging, and

outwards into the position shown at'III Ia in Figure8 when it comes to'r'eston the cylindrical "clutch rollers 81 slip and'th'edie is notrotated.

In the example illustrated of a four-land diefthe notch I02a now engagedby the toothIM is exfinally the point of the tooth I04 has beenlrockedactly at 90 to the notch shown engaged'by the tooth I in Figure 8, sothat themachin'e is ready for a similar grinding cut on the next land ofthe die, and indeed the cut is made exactly at 90 fromthat made on thefirst land.-' It is made of exactly the same shape due to'the use of thepattom 54 and to exactly the'same depth due to the permitted traverse ofthe crank feed'handle 94. Therefore, when allfour lands have beenground,

is spaced exactly at 90 from 'the'corresponding their leading faces areground to exactly the same I point 'on the next land so that an entirelyuniform and satisfactory flnishis produced on the die.

In the drawings, the die is prevented from moving in the holder 80 fromtheshelf '8I by a tubular clamping member "I I5 which can be insertedinto the holder'on top'of the die 82. It

hasa number of peripheral projections I I6 which can enter the dieholder through slots III (Figure 2a), and on rotating the clampingmember- II5 by handles II 8, the projections II6 ,,enter cam grooves H9with inclined upper surfaces so that the clamping, member H5 is firmlypressed down on the top of the die 82.\

After a certain number of operations, the

grinding. pencil '28 has become. glazed and its surface needs,redressing. Thenfthe die 82 is removed from the holder 80 and a wheeldresser is inserted in its place. This is illustrated in Figures 13 to15, in which the same references have been used for corresponding partas in Figures '7 and 8. The wheel dresser consistsof a body I20 ofthesame shape externally as a die and with the wheel dressing tool I20which is formed with an upwardly extending boss I26 centrally bored toreceive the gaugel25 as shown in Figure 14. The point I22 of the diamondis just brought up to the'outer surface of the stem I21 of the gauge I26and then the diamond is locked in that position-by aset-screw I24. Thegauge I25 is re-v moved and the wheel dresser IZO placed in'th'e dieholder 80 and clamped intov position by the clamping sleeve I I5. Thenthe grinding pencil is set'into rotation by admitting the compressed airsupply and the machine set into operation. The grinding pencil 28 ismoved-slowly to the left in Figures 13 and 15 by moving the whole of thedie holder assembly to the left byu nlock ing the. screw I9 andoperating the indexing wheel I6 so that the whole of the die holder assembly moves on the slide surfacesIB.

During this sliding movement the tappet heads 59, remain in engagementwith the rollers 65, 66 since the tappet heads are made large enough toensure this.

When the grinding pencil 28 is 'sufiiciently dressed, the wheel dresseris" removed from the die holder and the transverse slide is left in theposition which it has reached and is locked in that position bytightening the screw I9. The refsult is that when the die or a fresh dieis placed in the die holder, it is slightly displaced in position'fromthat which a die occupied before the grinding pencil was dressed by anamount equal to thecut taken off the wheel in the dressing operation bythe diamond I22. Therefore, when grinding of the. die is resumed or afresh die is ground, the grinding pencil 28, although slightly reducedin diameter, takes exactl the samecut -upon'operating the crank handle94 whichjit would have taken if it had not been reduced in diameter andthe'die holder had not been moved transversely. I

The invention has been illustrated and described with, particularreference to the grinding and finishing of a button type screw die withfour lands spaced at 90 apart,lout it is clear that the machine by useof a suitable 'worklholder, can beused for grinding any metal partsthatrequire asimilar finish. Thus, for examplelthe invention is applicableto the grinding of thein+ ternal teeth of annular gears.

'Iclaimz' g 1. In a machine for grinding the lands of button screw dies,the combination of a dieholder mounted for rotation about the axis of adie'carried in said die holder, a spindle journalled to rotate about anaxis parallel to that of said die holder, 'a grinding tool mounted onsaid spindle,

a support carrying said spindle for rotation about said axis, powermeans operatively connected handle, stop members mounted in the path ofsaid handle for: limiting the movement of same in both directions, andgearing connecting said feed handle tosaid die, holder to rotate the;-latthe -cut.-

.ter about the axis of the dieto produce ,tingufeedduring'grinding.' a

32; In a machine for grinding the t me ton screw dies, the combinationof;adie holder .mounted for rotation about the axis or a die ear; triedin said die holder, aspindlejournalled to tate about an axis parallel tothatof said die,

holder, ;power means :for rotatin'g said spindle, a

produce the cutting feed during grinding, 1 3. 'In a machine forgrinding the lands 'ofbut-1 ton screw dies, theflcombination of a dieholder: mounted for rotation about'the axis ofia die oar-1 ried in saiddie' holder, a spindle journalled to rotate about an axis paralleltothat of said die holder, power means for rotating said-spindle, a; a.pantograph linkage provided with a tracing sty-i lus a support for saidspindle mounted on one member of said pantograph linkage, a pattern;

, support; located in position to be' traversed by .said tracing stylus,a rotary feed handle and,

gearing connecting said feed handle to said die holder to rotatethelatter about the axis of jthe die to produce the cutting feed duringgrinding.

4.11m a machine for grinding the lands of but-5 J ton s'crewdies, thecombination of; a die holder .mounted for rotation about th axis offadie;

carried in said die holdenga spindle journalled to rotate about an axisparallel to that of said;

i dieholder, a support for said spindle, power means for rotatingsaid-spindle, means tor-mov ing-saidgsupport to effect movement of saidspindle along v a --predetermined path conforming to the profile to beground, a rotary reed handle, gearing connecting said feed handleto saiddie holder to rotate the latter about the axisof the die .to producethecutting feed during grinding, and-anadjustable stop'locatedtoco act withsaid I Jess handle to limit the maximum amount of the engine feed.

holder, power means for rotating said spindle, a pantograph linkageprovided with a tracing stylus, a support for said spindle mounted onone member of said pantograph linkage, a pattern sup-w l located inposition to betraversed by said} tracing stylus,"a'rotary feed handle,gearing con--:

meeting said feed handle to said die'holder to rotate the latter aboutthe axi's' of the die to? produce the cutting feed during grinding andan. adjustable stop locatedto co-act w'ith' said," feed. handle to limitthe maximum amount ofi.

? the cutting 'feed.

"a m a.m'achine for grind ing the land or but-i ton screw dies, thecombination of a die holder mountedior rotation about the axis of adiecarried in said the holder,: a spindle journalleditq' rotate about an axs parallel to that ofsaiddie holder, .a support for said spindle, powermeans for rotating said spindle, means 'for moving said support toeffect movement ofsaid spindle along a a predetermined path conformingto theprofilej v tobe ground, a rotary feed handle, gearing connectingsaid feed handle to said die holder to rotatathe latterabout the axis ofthe die to 1 i r a machine for; grinding the'lands of butL ton screwdies, thecombination of a die holder mounted fOr rotation about the axisof a die cartied in said die holder, a spindle journalled to, rotateabout an axis parallel to that ofa-saidgdie produce-theyfiuttingiced z qv 'i a one-way clutch interposed-between said teed handle and'said dieholder; to perm-it s mdie,

holder to'turnforwardly while said feed handle-is stationary; I I 7 a nperforming a pluralityf grinding operations-atgspaced angular positionsOn a metal workpiece, the' combination of-a -stationary machine frame, awork-holder mounted for rotation-in said frame,- a grinding wheelspindle journalled to rotate about an axis parallel f to that of saidwork-holder; a support for said spindle, powerjmeansfor-rotating "saidspindle, a:

work-holder registering device comprising; a ,re-

siliently actuated pivoted toothlocated toi engage I a notch in each ofa plurality of angular positions of said work-holder, means for movingsaid support to eifect a predetermined relative movement betweensaidspindle and said work-holder in each of the angular positions ofsaidworkholder and manual means for rotating said work;- holder to producethe cutting feed during each of a plurality of grindingoperationa I "8.In a machine forgrinding the landsof buts ton screw dies, thecombination ofastationarymachine frame -adie holder mounted --for rota-I tion in said frame and furnishedhwit-h a;plural ity of angularlyspaced peripheral notchenya grinding wheel spindle journa'lledtorotateabout 1 anaxis parallel to that of said die holder, Ia

- supp orspindlegpo rv mea s for-rotat .ing; said spindle, aresiliently; actuated pivoted tooth located toenga'ge ineach ofsaidnotches I to registersaiddieholder in a plurality organton screw dies,the combination of a stationary machine frame; a die holder mountedjforrota-= ti n-in-said frame and iorm'edwith a peripheral rim furnishedwith a-plurality of angularly spaced gular positions,'- means for movingsaid support to cause a predetermined-relative movement-betweensaidspindleand said die holder'iin each o nih ansarms s o e lat riian imnual meansor sa d'adie hol r t predu e h cutting feed during 'eachof aplurality of grind ingoperationa '9.- In gamachine for grinding thelands of butnotches, a grinding Wheel-spindle journal-led to rotateabout an axis paraIleltothat of said die holder, a support for saidspindle, power means for rotating said spindle. a rotary feed handle.earingwconnectingsaid feed handle to said-die holder to rotate thelatter about the axis of the dieqto produce the cuttingfeed-duringgrindin a resiliently-actuated tooth pivoted to said machine frameinposition to engage each: of said notches to register said-die holderin a plurality of angular positions and means for movin said support :tocause a-predeterminedrelative movement between saidspindle-and sa d dieholder in eachof the angular positions of thelatterv @110;In-amachinefor grindingthe lands of but- '.ton screw dies.the'comhination of a stationary machine frame, a die holder mountedforrotation in said trame and formed with aper iphera'l rim furnishedwitha, plurality of angularlv spaced notches, a grinding wheel spindlejournalled to rotate aboutjan axisparallel to that of said die holder. asupport for said spindle, power means "for rotating said spindle, arotary fe'ed handle,

gearing conneoting said feedhandletoisaid holder to rotate the latterabout'the axis of the die toproduce the cutting-feed during grinding,

a resiliently-actuated tooth pivoted to said ma chineframe'inposition toengage each of said notchesto register said-die holderin a. pluralityof. angular positions, means for moving said support to cause apredetermined relative movement between said spindle and said die-holderin each of the angular positions of the latter, and madjustable stoplocated to co-act with said feed handie to limit the maximum amountofthe cutting feed.

11. In a machine for grinding the lands'of button screw dies, thecombination of a stationary machine frame, a, die holder mounted forrota rim furnished with a plurality of angularly spaced notches, agrinding wheel spindle journalled to rotate about an axis parallel tothat of said die holder, a support for saidspindle, power means forrotatingsaid spindle ,-a rotary feed handle, gearing connectings'aidfeed handle to said die holder to rotate the latter about the axisof the die to producethe cutting feed during grinding, aresiliently-actuated tooth'pivotedto said'inachine frame in position toengage each of said'notches to register said die holder in a feed duringgrinding, a one-way clutch inter- P tion in said frame and formed withaperiph'eral plurality of angular positions and means for 12. In amachine for grinding the lands of but- 7 ton screw dies,.the combinationof a stationary machine frame, a die holder mounted for rotation in saidframe and formed with a peripheral rim furnished with a plurality ofangularly spaced peripheral slots, a grinding wheel spindle journalledto rotate about an axis parallel to that of said die holder, a supportfor said spindle, power means for rotating said-spindle, aresilientlyactuated tooth pivoted in said machine frame in position toengage each of said notches to register said die holder in a pluralityof spaced angular positions, meansfor moving said support to causea'predetermined relative movement between said spindle and said dieholder in each of the angular positions of said die holder, a rotaryfeed handle, gearing connecting said feed handle to said die holder torotate the latter about the axis of the die to produce the cutting feedduring grinding and a one-way clutch interposed between said feed handleand said die holder to permit saiddie holder to turn forwardly whilesaid feed handle is stationary, each of said notches being shaped on oneface to cause disengagement of saidresiliently-actuated tooth during therotation of said die holder by said feed handle in effecting each of aplurality of grinding operations. i

13. In a machine for grinding the lands of but: ton screw dies, thecombination of a stationary machine frame, a die holder mounted forrotation in said frame and formed with a peripheral rim furnished with aplurality ofangularly spaced peripheral slots, a grinding wheelspindlejournalled to rotate about, an axi parallel to that of said dieholder, a support for said spindle, power means for rotating saidspindle, a resilientlyposition to engage each of said notches to regofthe angular positions of said die holdere rotary feedhandle, gearingconnecting said feed handle to said die holder torotate the latter aboutthe axis,of the die-to produce the cutting posed between said feedhandle and said'die holder to permit said die holder to turn forwardlywhile said feed handle is stationary;'and an adjustable stop located toco-act with said feed handle to limit the maximum amount of the cuttingfeed during each of a plurality of grinding operations, each. of saidnotches being shaped on one face to cause disengagement of saidresiliently-actuatedteeth during the rotation of said die holder by saidfeed handle ineffecting each of said grinding operations. l

14. "In a machine for performing a plurality of grinding operation at,spaced angular positions on a metal work-piece, the combination of astationary frame, a work holder mounted for rotation on'said frame andfurnished with a plurality of 'angularly spaced peripheral notches, a

. grinding wheel spindle journalled to rotate about an axis parallel tothat of said work holder,

powerfmeansfor rotating said spindle, a p'antograph linkage providedwith a tracingstylusja support for said spindle mounted on one member ofsaid pantograph' linkage, a pattern support located in position to betraversed by saidtracing stylus, a resiliently-actuated tooth pivoted insaid machine frame in position to engage each of said notches toregister said work holder in a plurality of spaced angular positions, arotary feed handle, and gearing connecting said feed handle to said workholder to rotate the latter about the axis of the die to produce thecutting feed durmg each of the plurality of grinding operations.

15. In a metal grinding machine, the combination of a stationary machineframe, a work 'holder mounted for rotation and guided for axialreciprocation in said machine frame, a grinding wheel spindle journalledto rotate about an axis parallel to that of said work holder, a supportfor said spindle, power means for rotating said spindle, a camshaftjournalled in said machine frame, cams on said cam shaft co-acting withsaid work holder to effect reciprocation of same,

in said machine frame, means for moving said support to cause movementof said spindle along a predetermined path, and manual means forrotating said work holder to produce the cutting feed during grinding.

"ment of said spindle along a predetermined path,

actuated tooth pivoted in said machine frame in Y about the axis of thedie to produce the cutting 16. In a machine for grinding the lands ofbut ton screw dies, the combination of a stationary machine frame, a dieholder mounted for rotation and guided for vertical reciprocation, insaid frame about the axis of a die carried in saiddie holder, a'grindingwheel spindle journalled-to rotate about an axis parallel to that ofsaid die holder, a support for said spindle, power means forrotatingsaid spindle, a horizontal cam shaft journalled in said machineframe, cams carried H by said cam shaft and co-acting withsaid dieholder to effect vertical reciprocationof same, meansfor moving saidsupport to cause moveconforming to the profile to be ground, a rotaryfeed handle and gearing connecting said feedhandle to said die holder torotate the latter feed during grinding.

ister said die holder in a plurality of spaced ani 17. In a metalgrinding machine, the combination of a work holder mounted for rotation,a

grinding wheel spindle journalled to rotate about tween said .spindleand said die "holder'in. each'y an axis parallel to that of saidworkiholder pa support for said spindle,,compressed air motor having itsrotor secured tosaid spindle, a conduit for supplying compressed air tosaid air motor, a manually-operated valve for controlling airjflowthroughsaid con'duit,'means for moving said support to cause movement ofsaidspindle along a predetermined path, and manual means for rotatingsaid work holder to produce the cutting feed during grinding, I g

l8. In a machine for grinding the lands of but ton screw dies,the'combination, of a die holder mounted for rotation aboutthe axis of adie carriedin said die holder, a grindin Wheel spindle journalledtorotate'about an axis parallel to that I of said die holder, a compressedair motor having its rotor securedtosaid spindle, a conduit forsupplying compressed air to said'air motor, a

manually-operated valve for controlling air flow through said conduit, asupport for said spindle,

' means for moving said support to cause movement of said spindlealong'apredetermined path er mounted forrotation and mounted in saidmachine frame .toslide transversely to its axis'of rotation; means forlocking said work holder in said machinegframe after sliding into apredetermined position, a grinding wheel spindlejournalled torotateabout an axis parallel to that of said work holder, a support for saidspindle, pow er .means for rotating said spindle, means formoving saidsupport to cause'movementof: said spindle :alonga-predetermined path,and manual I means for rotating said work holder to produce the cutting.feed during: rinding.

20. In a machine for'grinding the, lands of but ton screw dies, thecombination of a stationary. machine frame, a horizontal slide carriedinsaid frame, a die holder'supportedon said slide and mounted for rotationabout the axisof a die car- 'ried in said die holder, a lockingscrew forlockconforming to the profile to be ground, a'rotary feed handle, andgearing connecting said feed handle to said die holder to rotate thelatter:

ing said slide in a predetermined adjusted position in said frame, agrinding wheel spindle journalled to rotate 'about'an-axisparallel tothat of said die holder, a support-for said spindle, power means forrotating said spindle, means for moving said support to cause movementof said spin dle along a predetermined path conforming to the profiletobe ground, and manual means for rotating said die holder about'the axisof the die to produce the cutting feed during grinding.

' EDGAR. BANNISTER.

